Tree knocking is considered to be an effective way of communicating with Bigfoot. The theory is that Bigfoot uses this technique of wood knocking to alert other Sasquatch of the presence of humans. They have been known to respond to knocking, perhaps thinking it is other Bigfoot guys. I took this video in the Richloam track of the Withlacoochee State Forest in Sumpter County Florida. People think they have seen things in this vid. You be the judge.